Flattening substrates is essential for producing semiconductor power devices. However, substrates of wide band gap semiconductors composed of, for example, silicon carbide (SiC), gallium nitride (GaN), diamond, are hard and fragile, so it is difficult to efficiently flatten said substrates by mechanical processing.
Patent Document 1 discloses a manner of using slurry including abrasive particles and micro-nano bubble water.
Further, Patent Document 2 discloses a polishing method for reducing polishing defects and polishing works at a high polishing rate, in which a first processing liquid including abrasive particles and a second processing liquid including electrolytes and micro-nano bubbles having diameters of 10 nm-1000 μm are used.